Apple’s iPhone 6s and iPhone 6s Plus are expected to be announced on September 9th, during a yet-to-be-confirmed Apple media event that should already be in the works. Meanwhile, the constant stream of iPhone 6s leaks keep pumping out more rumors, with some more believable than others. A photo of a supposed retail box for the iPhone 6s Plus was taken somewhere in China recently, and it might bring some details that iPhone users won’t appreciate: the new iPhones might have smaller batteries than their predecessors.

According to cnBeta, the iPhone 6s Plus retail packaging shows an image of the device with a fish wallpaper (no, that’s not what you should be worried about). While the unfolded box (see following image) appears to be genuine, bearing the usual markings you expect to see on an iPhone retail box, it’s not in line with Apple’s most recent iPhone packaging.

Moreover, the wallpaper isn’t available in any of the iOS 9 beta versions released to date, and the box appears to be made of a material that’s thinner than previous boxes. However, a new report from 9to5Mac says the image might be genuine, and the koi fish in the picture might actually be a motion wallpaper similar to the ones on the Apple Watch.

Comparatively, the iPhone 6 and iPhone 6 Plus boxes don’t have images on the top side. Instead, an embossed profile of the phone inside the box is shown on the top.

Now, for the bad news.

The Chinese tech site also notes that according to the box, the iPhone 6s will have a 1,715 mAh battery (down from the iPhone 6’s 1,800 mAh battery) and the iPhone 6s Plus will have a 2,750 mAh battery (down from the iPhone 6 Plus’ 2,910 mAh battery). Japanese tech blog Macotakara says it also heard the battery capacity for both models will be lower, and some previous iPhone 6s rumors have made the same claim.